I have a bluetooth trackpad and a pair of bluetooth headphones and ever since I upgraded to Yosemite I've been having problems with both.
The trackpad fails to re-connect after the laptop wakes up more often that it before as do the headphones, on top of that the headphones are a lot choppier, to the point I can't listen. When connected to my phone they work flawlessly.
I'd unpaired & re-paired both devices & also removed them by deleting them from the .plist file directly, this improved things for a few days, but now it's back to the same problem.